FIG. 1 is a structural view of a mobile communications system in a related art. As shown in FIG. 1, the mobile communications system is mainly composed of a Core Network (CN), a Radio Access Network (RAN), and a terminal. The CN therein is in charge of a Non Access Stadium (NAS) affair, such as terminal location update and etc. and the CN is an anchor point at a user plane; the RAN includes a base station, and is mainly in charge of an access stadium affair, such as radio resource management. A physical or logical connection may exist between base stations according to an actual situation, such as the connection between base station 1 and base station 2, or between the base station 1 and base station 3, as shown in FIG. 1. Each base station may also be connected with one or more CN nodes in the CN. The terminal is User Equipment (UE), and the terminal may be any device which can communicate with the CN, such as a mobile phone, a tablet computer, a notebook computer, and etc.
Currently, following network elements are included in the CN:
A Mobility Management Entity (MME) or a Serving General Packet Radio Service Support Node (SGSN) is a unit which is for managing terminal access control, location information update and switch in the CN, and is for NAS signaling control from the CN to the terminal and for registering the terminal with the CN;
A Home Subscriber Server (HSS) or a Home Location Register (HLR) is an entity for preserving information in the CN, such as authorization information, authentication information, identity information, and subscription data of a user, and etc. According to different situations, the HSS or the HLR may be used to preserve the identity information of the user, and the binging information of the user and the terminal, or the HSS or the HLR may only preserve the identity information of the user while the binging information of the user and the terminal is preserved by a network manager, or the HSS or the HLR may directly preserve the identity information of the terminal. The HSS or the HLR is also for maintaining a subscription database of the user, and executing identity identification and authorization of the user and etc. A service platform make a query to the HSS or the HLR to obtain the identity information of the user or the identity information of the terminal.
A Packet Data Network-Gateway (P-GW) is located at a user side, and its main function is Internet Protocol (IP) address allocation, dialogue management, Policy and Charging Rules Function (PCRF) selection, route selection and data forwarding, Quality of Service (QoS) control, charging, policy and charging enforcement, and etc.
An Inter-Working Function (IWF) entity is a connection entity located between a mobile communications network and an external public network, and can implement functions such as protocol conversion, address inquiry, information preservation, and etc. The IWF may externally be connected with a Machine Type Communications (MTC) server, and may internally be connected with the HSS or the HLR, or a CN network element such as the MME or the SGSN, and etc.
An MTC Authentication Authorization Accounting (AAA) server, which belongs to a Home Public Land Mobile Network (HPLMN), provides a function of translation from an internal identifier of the terminal in the mobile communications network, such as an International Mobile Subscriber Identification Number (IMSI), to an external identifier at a network export. The MTC AAA server may be arranged to return the EID of the terminal according to the IMSI of the terminal, or may also be arranged as a Remote Authentication Dial In User Service (RADIUS) or a Diameter proxy server between the P-GW and an AAA server in an external Packet Data Network (PDN).
The EID of the terminal should be unique overall, and includes the following two parts:
1. A Domain Identifier (DID), which identifies a domain name controlled by an operator of one mobile communications network, wherein this domain name is for identifying an access address of a service provided by the operator, such as the service provided by the MTC-IWF, and the operator may use different DIDs to support different service accesses;
2. A Local Identifier (LID), which is managed by the operator of the mobile communications network, and is for exporting or obtaining the IMSI of the terminal; wherein the LID is unique in an application domain.
With regard to certain services, if a monitoring and management system needs to obtain monitoring data from the terminal, the terminal needs to be triggered through a server to establish a connection with the server, so as to report needed data to the server through the connection established with the server. After the terminal receives the trigger message from the server, the terminal needs to be able to respond immediately and establish the connection with the server. Currently, in order to meet a trigger requirement of the server to the terminal, the EID of the terminal is used to perform communications between the MTC server and the CN, and a corresponding relationship is stored between the IMSI and the EID of the terminal in the CN in an existing solution. However, the terminal only has one IMSI, but may have one or more EIDs, therefore, if the terminal has more EIDs, then the CN may obtain multiple EIDs according to the IMSI, as a result, which EID to be used cannot be determined, thus resulting in that the CN incorrectly responds to a terminal trigger request of the MTC server.